What prasadams you do depends on your time availability and capacity to prepare them. If nothing, at least make some Payasam and Vada etc. along with rice which you may do daily. You can do this yourself. I have been helping my wife do this for the last 28 years or so. This is not a difficult pooja. Get the Vradha Pooja Vidhanam book. - The goddess is seated in a palagai and decorated and placed near the entrance inside. A vilakku is lit. The offerings like a part of things - Coconut, flowers, fruits are also kept there. After a karpoora harathi there, the mother goddess is invited into the house either before or after rahukalam - lakshmi baramma or lakshmi rave ma intiki etc.are sung then. Bring the goddess with help from other ladies nearby and bring all the pooja items along with her. Pooja Starts with a Ganapathi pooja - Ganapathi is made of Haldi - Haridra - Manjappodi - in a small cone like shape and he is worshipped in that way. If you have a Ganapathi murthy, the same also could be worshipped. and after that Sankalpa (for which you should check the month, paksha, tithi, vara, nakshatra etc.) and main pooja takes place after that - at the end there is dhoopam, deepam, naivedhyam etc. There is also a small ritual of Saradu (thread) tied. If you find another lady there she may do it for you. You must also give saradu to that lady. If none is there, your husband may do it. While you do the saradu, generally the prasad (thengai moodi - half - for the lady of the house it is the bottom and visitor lady the top portion) should be given in hand along with flowers, banana, vetrilai pakku etc. If the vadhyar performs he is also given the vayana danam, i.e. the prasad is also given to him. After the ganapati pooja, there is main pooja which goes after sankalpam. There is also a padadhi kesantha pooja which is an anga pooja. You can do the ashtothra after doing some slokas. Nobody gets perfection the first time. We forgot to break the coconut first time. Do not hesitate, do it, slowly you will recollect how your mother used to do, how your grand mother used to. More than anything, your sincerity and intent matters than what you do. The nonbu starts with sraddha that you offer a day for the mother goddess lakshmi. Pathram Pushpam Palam Thoyam, yo may bhakthya prayachhathi says the lord. At the end there is also a kshama prarthana. You can do simple things.
Some arrangements :
Vetrilai pakku - keep 3 sets (2 vetrilai and 1 pakku - better to use Patnam Pakku)- one for Ganapathi Pooja, one for Prana prathista (if done with help of Vadyar or if husband could do it for you) and one for the last main offering.
Get Mangalakshata arranged - take a spoon or two of rice and add some Manjappodi and some drops of water and mix them and rice gets the proper color. Allow it to dry.
Get Chandanam, Kumkumam, flowers arranged. If roses are purchased and used for archanai, then keep the petals arranged by removing the stem and leaves etc. Chandanam could be made into paste at home or you can buy and keep. Kumkum, Manjal podi are available.
Arrange remaining things like Sambrani, Dasangam, Soodam (Karpoor or Camphor)
Generally, these things are kept ready in the Pooja Room.
If you can wear madisar it would be okay. Actually, madisar brings some commitment for the pooja. If inconvenient, you do it in your normal sari. I am not a professional vadhyar or even not formally trained. I have learnt it because we remained in places where we could not get vadhyars.
Madam, doing the pooja is important and your sraddha. Remaining things happen.
Aavahanam na janami, Na janami Visarjanam, Pooja Kramam na janami, kshamaswa parameswari is said at the
end meaning I do not know the method to start the pooja, nor the method to end it, neither the various steps mother goddess forgive me.
You can chant all the known lakshmi stotras like Kanakadhara stotra of Adhi Shankaracharya. It improves with time and you yourself will be competent to teach a few other suvasinis. You are a lakshmi yourself by name and she will take it from you and bless you.
You asked for the prasadams - people do even Iddli and modak, appam etc. On the previous night the ladies avoid rice as Pongal is offered and taken and also on the pooja night too. They eat the palaharams.
The next day is supposed to be a Punar Puja meaning you do all that you had done. However, if time does not permit, you can do a normal puja like offering Naivedya, Karpoora Haarathi etc. and chanting known slokas.
Practice will make you perfect.
best wishes
Ramamurthy